BBK SSI-R Intake Test: Short and Sweet

Horse Sense: If a new 5.0 intake manifoldmakes you feel, uh, dated, let's say our first dyno test for what wouldbecome this magazine was on small-block intake manifolds. That was 18years ago--the EFI 5.0 was entering its second year, the test was doneon an engine dyno because good chassis dynos were five years in thefuture, and the intakes were all carbureted, as there were no EFImanifolds to test.

In the now long history of the 5.0 H.O. engine, trends have come, gone,and returned. This article's focus--the spanking-new short runner SSI-Rupper intake manifold from BBK--is a great example of such circuitoushardware. It follows a relatively brief but storied list of short-runnerintakes from Downs Ford, Hartman, Texas Turbo, and others. Long out ofthe limelight, those intakes can now count the SSI-R as their spiritualsuccessor when it comes to making high-rpm power.

The short-runner 5.0 intakes trade almost all of the 5.0 H.O.'s strongbottom-end torque for improved top-end breathing. That's because themajority of the 5.0's prodigious torque is made courtesy of its long andnarrow intake runners, and the so-called box intakes neatly eliminatethe entire length of upper intake runners and replace it with a large,open plenum. While many have tried, these intakes have proven fairlyunsuitable for street work, but quite suitable when paired with theright engine tuning for track duty.

What's the right engine tuning? It's either a robust supercharger or aneye-watering, high-rpm, naturally aspirated strip engine. Either ofthese combinations moves the high volumes of air that a large-plenum,short-runner intake such as the SSI-R is designed to handle. Whenmatched with the proper engines, an intake such as the SSI-R is a thingof beauty. The engine responds with big top-end horsepower gains andtunability. For those who have worked their way up to semi-race engines,fitting such a racy intake is often a breakthrough moment when thelogjam finally clears and real power gains are made.

On the other hand, fitting a short-runner intake to a stock or mildbolt-on 5.0 is about as much fun as wet tennis shoes. Soggy down low tothe point of exasperation and unable to capitalize on top-end powerbecause the heads and camming can't support such top-end power, the boxintakes sometimes bear a bad rap they don't deserve. There are, afterall, more poor tuners than there are poor parts.

As expected, the SSI-R is an outgrowth of BBK's recently introducedSingle Stage Intake, or SSI, which is a more traditional, bolt-on-stylemanifold that uses a unique lower casting with runners optimized forheight and straight runs to the cylinder-head ports. The upper SSIintake casting is truly its own piece--standing out in the crowd with atwin-plenum design and curving, relatively generous-length runners. Dynotests have shown the SSI tries hard to maintain low-end torque while atthe same time running with such bolt-on favorites as the tubular GT-40.That's a tough job, and the SSI seems to have its moments at both endsof the dyno sheet without running away from anyone at either end. But ifanything, the SSI shows a penchant for top-end power as it hangs ontoits power curve notably longer than other intakes in its class.

The SSI-R uses the SSI's lower casting, while replacing the SSI'sstock-type runner length with what can be too-briefly described as anopen box of a plenum. The idea is to have a generous volume of air onhand downstream of the throttle body, and with little runner length toimpede airflow.

What It'll Cost

At press time, the SSI intake was in full production, but the SSI-R wasjust coming online at BBK. By the time you read this, the SSI-R shouldbe available. All prices are retail; street pricing should be less.

Thus, when an intake valve opens, a generous weight of air is primed tohead down the appropriate intake port. But at low rpm, the big plenumarea absorbs the signal from the opening intake valve, and air responseis sluggish. Torque suffers, and the driver wonders what happened to histhrottle response. But when rpm is high, the energy impacting the plenumfrom each intake-valve opening is strong, and a significant portion ofthe huge plenum is drawn into the cylinder.

We went to Brothers Performance Warehouse, the retail arm of BBK, towatch BBK technician Brian Rogers run both the SSI and SSI-R intakes onhis 331-powered '93 Mustang Cobra. As we all knew going in, Brian'smostly bolt-on engine was likely not enough powerplant for the SSI-R tostrut its stuff. But with the high-rpm nature of the SSI-R essentiallyensured just by looking at it, everyone involved was curious to see howit did in the more difficult transitional area between a bolt-on and adedicated strip engine. With Brian's car lightly cammed and sporting afew extra cubic inches, it would prove a tough customer for the SSI-R.

The testing also allowed us to see the SSI-R installation procedure.There's little to it, really. The SSI upper is removed and the SSI-Rbolted in its place; aside from moving the throttle body from one upperto the next, along with a few minor fittings, the SSI-R pops right on.Intended for off-road applications only, the SSI-R does not accept theEGR valve like the SSI upper does, but you could probably use the stockEGR spacer if you wanted. There are enough vacuum ports for the usualchores, and hood clearance is close but not a worry with the stock hood.Stock intake hoses and throttle cables work fine, too.

So, what did Brothers' chassis dyno think of the SSI and SSI-R? Asexpected, the SSI turned in a respectable 327 hp at 5,100 rpm to therear tires, and the SSI-R bumped up the power peak to 346 hp at 5,350rpm for a healthy 19hp gain. Torque, of course, was the commodity beingtraded, with the SSI making 374 lb-ft at 4,100 rpm and the SSI-R trying,but coming up 11 lb-ft short with 363 at a loftier 4,350 rpm. Where theSSI-R starts to gain over the SSI is 4,850 rpm, a rather high numberconsidering the camshaft--and maybe the cylinder heads--was signing offby 5,500 rpm, so the SSI-R's obvious top-end personality was easilyconfirmed.

As it turned out, Brian's car was not enough for the SSI-R upper intake,but it was close. We plugged the numbers into the Dynojet's drag-racesimulation, where the SSI just pipped the SSI-R. With a bit more underit, the SSI-R would triumph, which leads us to believe the SSI-R isprobably a little more torque-friendly than the old-school box intakes.While we haven't tested it, given the SSI-R's large runners in the lowerintake casting, combined with the huge, smoothly shaped plenum area, webelieve the SSI-R will sparkle given boost or big rpm.

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Also, the 331ci small-block had to help some, but this test clearlyshows it takes more than an eighth of an inch of stroke to keep arace-type intake manifold on the boil. Even a 347 wouldn't be enough byitself, but such a short-block would also need aggressive camming,cylinder heads, and generous rpm to make the SSI-R do its thing.

BBK says the SSI-R will be available in quantity by the time you readthis. It's a no-brainer, as the upper intake is the only major hardwareyou'll need. At first, expect to find the SSI-R as a full intakeonly--not as an add-on upper casting only. Look for it at the 'strip.

Dyno Results

BBK SSI

BBK SSI-R

Difference

RPM

POWER

TORQUE

POWER

TORQUE

POWER

TORQUE

2,600

159

322

160

322

1

0

2,850

185

341

182

336

-3

-5

3,100

210

355

201

341

-9

-14

3,350

231

362

222

347

-9

-15

3,600

251

366

238

347

-13

-19

3,850

272

372

257

351

-15

-21

4,100

292

374

278

357

-14

-17

4,350

307

371

301

363

-6

-8

4,600

319

364

311

355

-8

-9

4,850

326

353

325

352

-1

-1

5,100

327

336

338

348

11

12

5,350

324

318

346

340

22

22

5,600

321

301

344

322

23

21

5,850

312

280

335

301

23

21

Testing was conducted at Brothers Performance Warehouse, the retail armof BBK, using a Dynojet inertial dyno. See the sidebar for details onthe test-car profile.